“Like to have a prod at him?” said the captain.

Jack hesitated a moment, and then said, “Yes.”

The captain nodded approval, but did not hand the boat-hook.

“Better let me,” he said. “You shall have a turn with a lance, first chance. Look, here he comes. Wonderful how these things can move through the water. You can’t see him moving a fin, but he is rising slowly, and when he likes he can dart through like an arrow. One lash with the powerful tail sends the brutes a long way. I believe he is rising now from some management of the air-bladder. Swells himself out and makes himself lighter.”

Jack made no reply, for he was half fascinated, as he gazed down into the water, by the way in which, after passing under the canoe, the shark gradually and almost imperceptibly rose, with its head toward them, the sharply-rounded snout projecting over and completely hiding the savagely-armed jaws.

“Sit fast and don’t move,” said the captain, poising the little boat-hook; “he is sure to lash out, but it will be behind, and can’t touch the boat.”

Only a few moments passed, but expectation made them seem minutes, during which the shark’s head came nearer and nearer, and its shadow cast by the sun was perfectly plain on the sands a few feet below.

Then with all his force the captain drove the pole down; the aim was good, for the next instant there was a tremendous swirl in the water, the long, heterocercal tail, through which the creature’s spine was continued to the end of the upper lobe, rose above the surface, and was brought down with a tremendous blow which raised a shower, and at the same time Captain Bradleigh’s arms were dragged lower and lower, till he loosened his hold, and the pole of the boat-hook disappeared.

“I didn’t mean that, Mr Jack!” he cried, laughing, as the boat danced up and down, and the lad sat waiting to fire if the need arose. “My word, what a tug! Enough to jerk a man’s arms out of the sockets.”

“Will it attack us?” said Jack.